Electric signaling system.



No. 843,550. PATENTED FEB. 5, 1907. F. W. PRENTIGE.

ELECTRIC SIGNALING SYSTEM.

APPLICATION I'ILED MAB. 24. 1906.

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P. W. PRENTIGB, ELECTRIC SIGNALING SYSTEM.

APPLICATION FILED MAR. 24. 1906.

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ELECTRIC SIGNALING SYSTEM.

APPLIQATION FILED MAR. 24, 1906.

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No. 843,550. PATENTBD FEB. 5, 1907.

P. w.- PRENTIGE. ELECTRIC SIGNALING SYSTEM.

APPLICATION .FILED MAR. 24. 1906.

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FRANK W. PRENTIOE, OF CHICAGO, ILLINOIS.

ELECTRIC SIGNALING SYSTEM.

Specification of Letters Patent.

Patented Feb. 5, 1907.

Application filed March 24, 1906. Serial No. 307,85?

' Electric Signaling Systems, 0 which the following is a specification.

My invention relates to electric signaling systems for railways, and more particularly cab and block-signal systems employing socalled Hertzian waves or like electrical oscillations for controlling signal devices upon a car or engine to indicate the condition of the right of way with res ect to the presence or absence of other ve -cles or witliregard to any of the usual conditions of danger or safety of the track within prescribed limits.

To this end the invention com rises a generator or transmitter of electrica oscillations for each block or section of the road, which is normally operative when conditions of safety maintain in the block or section to be guarded and is rendered inoperative or inert when conditions of danger exist, and receivers on the cars or engines influenced by the oscillations and adapted to control signal devices which indicate whether the section is safe or blocked.

Generically, the invention comprises a cab and block s; stem in which safety is indicated in a given block by the generation of oscillations in the transmitter controlling such block and in the car or cab by signal devices controlled by a receiver influenced by such oscillations, and danger is indicated by the absence of such oscillations and a consequent non-action of the receiver in the car or cab.

In the accompanying drawings, Figure 1 is a diagrammatic representation .of a sectional rail cab and block signal S;.S'. el 11 embodying the invention upon the east-bound track of a double-track railroad. Fig. 1 is an enlarged v fragmentary detail of the track-rela; 's and the contactscontrolled thereby Fig. 2 is a diagram of the apparatus on each car or cab or other vehicle. Fig. 3 is a fragmentary per- 5 ective view of a coherer or wave-responsive evice and appurtenant apparatus. Fig. 4 is a longitudinal section thereof. Fig. 5 is an end view of the same. Fig. 6 is a detail of the compressed-air valve controlled by the coherer. Fig. 7 is a fragmentary plan view of the mechanism for starting the emitter or generator of electrical oscillations; Fig. 8 is a side elevation of the emitter and the mechanism for starting the same.

Referring to Fi 1 of the drawings, 1 2 and 1 2 ineicate tie rails of two adjacent blocks or sections into which the track is (llVlQGd, Block No. 1 and Block No. 2. respectively. It will be understood, of course, that said sections being designated.

the west-bound track is similarly equipped,

as shown above, the apparatus being in reverse position to that shown in Fig. 1. In using a single track or line of road for moving trains in both directions on the one track or line of road each side of the trackis equipped with apparatus, as shown in Fig. 1, one on one side for west-bound and on the other side for east-bound trains, cars, cabs, or vehicles. The entire track or road is similarly divided into blocks or sections of any desired or prescribed length, each block defining the limits within whichbut one train, car, cab, or vehicle is allowed at one and the same time under proper conditions of operation, as will be understood by those skilled in the art.

Bridging the rails 1 and 2 of block No. 1 is a magnet 8, connected 'to the respective rails by wires 5 and 6 and including a battery 7. Said magnet 8 controls a pivotedarmature 9, which normally engages a contact 25, forming one terminal of the circuit of an emitter or generator of Hertzian waves or electrical oscillations 1?, whichcircuit includes a conductor 12, battery 13, back contact 14, and armature 15 of induction-coil17,

and wire 16, which leads from the other terminal of said induction-coil 17 to armature 9. v

When block Nb; 1 is not occupied by a car or train, armature 9 is attracted from magnet 8, closing the circuit through the inductioncoil or transmitter 17 and sending a series of electrical oscillations enerated at the sparkgap or terminals 18 of the secondary by way of conductor 19 to an overhead wire or conductor 20, paralleling and coextensive with the track section or block in rear of block No. 1. As long as block No. 1. is unoccupied these oscillations are generated and conducted along the wire 20, which serves the same purpose as the or-finary aerial to indicate 'upon any train or car entering the rear section by apparatus to be hereinafter described that a con'ition of safety maintains in block No. 1. pies block No. 1, the wheels of said train When a train or car occu- IIO which electrical oscillations are generated and propagated along a conductor 20, paralleling block No. 1, as long as said block No. 2 is unoccupied, and the said oscillations are discontinued when block No. 2 is occupied to incicate upon a car or train in block No. 1

that the former block is at danger. Similarly each other block or section is equipped to send oscillations along a wire paralleling the next blockin rear to incicate safety and to suppress saidoscillations to indicate danger.

It is to be particularly noted that the arrangement of the track and the generators or emitters of electrical oscillations controlled thereby, so that the existence of oscillations shall 11162103136 safety, and the absence of such oscillations shallinoicate danger, through the agency of any suitable receiver or responsive apparatus upon a car or train constitutes a complete and effective signaling system.

It is also to be observed that the combination of a track divided into blocks or sections with an emitter or generator of electrlcal oscillations in each section and receivers or responsive devices on the trams or cars operating on the track is genericallywithin the purview ofmy invention, proviced the presence of oscillations in agiven section shall indicate safety and the ab. sence thereof shall indicate dangers, even though the control of the oscillations be effected by means other, than track or rail circuitsas, for example, when an emitter or generator for a given block or section is controlled by the relative position of a semaphore, a switch -operating'. mechanism, a

draw-bridge, or any other apparatus or appurtenance of a railroad to generate oscillations when the way is safe and. to suppress such oscillations when it is dangerous for an on-- coming car or train to proceed beyond the next advance section.

To extend and increase the efficiency of the system, as hereinb efore described, and to insure a rapid, certain, and positive operation under all conditions, I provide auxiliary means for starting the emitter when the dan er condition has terminated. Referring to block No. 1 of Fig. 1 and to Figs. 7 and 8 will disclose this operation. The inductioncoil 17 is of course rovided with the usual form of make-andreak mechanism, com-.

prising the armature 15 and back-stop 14, the armature resting against the back-stops when the induction-coil is inactive andvibrating rapidly between the pole-piece of the induction-coil and back-stops when the coil is oper ating. It has been found that, owing to the inertia of the parts or from other causes, the armature 15 sometimes fails to be drawn away from the contact 14 when the circuit of the coil 17 is completed, with the result that no effective secondary current is induced in the coil and no oscillations set up at the terminals 18. In order to insure a positive action of the armature in starting the induction-coil, the armature is strucka blow to move it away from the contact 14 at the moment the circuit of the induction-coil is completed. This is effected by means of two brushes or wipers 102, Figs. 7 and 8,

mounted upon a rotary disk 101, which is driven by a train of clockwork 100, said brushes being so arranged that they strike the. curved end of the spring-arm of the armature 15'and force said armature toward the pole-piece of coil 17 every time the clockwork is actuated. The clockwork. 100 is A normally held inactiveby means of a pawl or detent 103, adapted to engage one of two ratchet-like notches or depressions 104 in the top disk 101, and said pawl is controlled by the armature of an electromagnet 28, which when energized attracts its armature and disengages pawl 103 from disk 101 and allows the clockwork to start. 28 is denergized, the armature falls away and pawl 103 engages the next notch 104 that passes under it and stops the clockwork.

Magnet 28 may be energized by any suitable arrangement of circuit that is adapted to be completed when the condition of danger in a given block or section is terminated. In the form of the invention illustrated the magnet 28 is energized when the car or train leaves the guarded block by means of a cir.

cuit 21 22,1eading from'a battery 23, and a magnet 24, placed in opposition to magnet 8 and connect ed, respectively, to two short insulated rail-sections 3 and 4 at the end of the too When the magnet I lus block, so that when the last wheels of a car or train leave rails 1 2 of block No. 1 and pass I over rail-sections 3 and '4 magnet 24 is momentarily energized, and as magnet 8 is then deenergized said magnet 24 attracts the armature 9, which has on its free end a tarily a circuit through magnet 28, whichis traced as follows: battery 26, wire 30, magnet 28, wire 27, disk 11, spring-contact 10 on armature 9, back to battery 26.

The circuit of magnet 28 is closed only tively assured, and the electric oscillations,

which indicate a clear block, are sent along the wire 20 as long as block No. 1 is unoccupied. It will be understood that a similar arrangement of apparatus is provided for each of the other blocks or sections to insure the proper positive starting of the respective induction-coils or transmitter of osci.lation.

As hereinbefore referred to, each car or engine is provided with a suitable receiver or responsive device which operates under the influence of the Hertzian waves or oscillations to effect a predetermined signal or indication on the car or engine. Such receiver and signal may be of any of the usual coordinations of Hertzian-wave-receiving devicessuch, for example, as an ordinary coherer and signal-circuit controlled therebywhich operates to close a local circuit to actuate the signal when a Hert-zian wave traverses or eflects the coherer and to open the. circuit and discontinue the signal when the" Hertzian waves or osc llations cease or are" interrupted, it being understood that the continuance of the signal or indication due to the transmission of the local circuit through the coherer, which the latter is rendered operative by the Hertzian waves, signifies a condition of safety as to the guarded block or section, and the discontinuance of the signal'by the interruption of the current at the coherer indicates a condition of danger.

In the present embodiment of this principle I provide in each .cab, car, vehicle, or train a signal apparatus comprising the following instrumentalities: A coherer 40 which consists of a generally cylindrical body having in two diametrially opposite faces recesses 41 and 46, each covered by a suitable cap or cover of glass or similar material. In 41 is placed suitable metal filings or other material that is responsive to ethereal waves, which cause the filings to cohere and transmit an ordinary voltaic current, but which when subjected to a slight jar or alteration in their relative positions interpose such high a resistance as to fail to transmit such-voltaic current. Traversing the cylinder 40 and having their inner terminals embedded in the filings in recess 41 are two conductors 42 and 42, which are connected with contacts 43 and 43 on the ends of the cylinder, said contacts 43 and 43 being adapted when recess 41 is uppermost to be engaged by brushes 44' wires 45 and 45" with a relay 57. Recess 46 is partially filled with some material that is normally conductive of voltaic currents such as mercury or the like, and two conductors 47 47', lead from the lower part thereof to two contacts 48 and 48, respectively, on the ends of the cylinder 40, which when recess 46 is uppermost areengagedby brushes 44 44, respectively, which connect, by wires 50 and 50, a magnet through a suitable battery to engage said magnet. Relay 57 controls, through its armature 58 and front stop 59, the circuit of a magnet 56, placed in opposition tomagnet 55, said circuit comprising leads 60 and 61 and a battery 62. Between magnets 55 and 56 is an armature 54, which normally tends to occupy a mid-position with respect to said magnets. On the end of said armature 54 is secured a segmental gear 53, which engages a pinion 53 on the shaft of cylinder 40, so that as said armature is attracted to one or the other of said magnets 55 and 56 the coherer-cylinder 40 is rocked through one hundred and eighty degrees, thereby bringing recess 41 or 46 thereinuppermost.

In the recess bearing post 52 of the coherer the shaft of cylinder 40 is cut away so as to form with the cylindrical hole forming the shaft-bearing a valved passage 72 and .connected therewith by two passages, as shown in Fig. 6, and two pipes 71 and 73, leading from a compressed-air tank and to bellows of a signal-controlling device, respectively. For both extreme positions of the cylinder 40 the passage-way 72 is closed by the shaft; but as the cylinder is rotated in one direction or the other connection is established during practically three-fourths of the movement between tank 70 and bellows 75, admitting air to the latter and causing it to expand.

The signal-controlling device consists of a casing 74, to the base of which is secured the generally cylindrical expansible bellows 75, having in its top an inwardly-opening valve 7 5, which closes when air-pressure is admitted and permits the air to escape slowly.

and 44, respectively, which are connected by 7 Secured to the top ofbellows 75 is a frame a 76, having at its ends rings or collars 79 80, which loosely engage vertical guides 77 and 78 and also serve to raise and lower two frames 82 and 83, guided on the rods 77 78 and carrying in their upper portions red glasses 84 and 85, moved by the contraction and expansion of the bellows 75 into and out of registry with two lenses 86 and 87 in casing 7 4, so as to cause alight 95 in the casing to show either red or white through said lenses, Guide 77 is preferably formed of a hollow tube, connected by a pipe 97 with airtank 70 and having at its outer end a whistle or similar alarm 89. In the lower part of said tubular member 77 is a spring-closed stop-cock 88, having a lateral arm adapted to be engaged by a detent 90 on ring 79 to open the valve and sound the whistle when out by induction-coil 17 the bellows collapses. Upon ring SO is a contact .91, which engages a fixed contact 92 at the base of rod 78 when the bellows collapses to close the circuit of a battery 94 and ring a bell 93. v

The cab signaling device as thus described operates as follows: When the car or engine occupies a block-as, for instance, block No. 1and-the adjacent block No. 2 is unoccupied, the Hertzian waves transmitted along wire 20 and radiating from said wire through the air pass-through and energize the coherer 40, closing thecircuit of relay 57, which closes the circuit of magnet 56, causing the armature 54 to move to the right and rotating the coherer through one hundred and eighty degrees, thereby disturbing the filings in 41, breaking the circuit of relay 57, and deenergizing magnet 56. Recess 46 is thereby brought uppermost, and the circuit of magnet'55 is momentarily closed, attracting armature 54 and returning the coherer 40 to its original position. As the coherercylinder rotates passage-way 72 is opened and air is admitted from tank 70 to bellows 7 5. As the coherer is rapidly rotated or oscillated to and fro by the recurrent action of magnets 55 and 56 as the material in 41 is successively cohered and decohered air-pressure quickly accumulates in bellows 75, and the latter is inflated, causing the red or danger glasses to be moved out of. registry with lenses 86 and 87 and showing a white or safety light. This condition will maintain as long as blockNo. 2 is clear, and the Hertzian waves are sent Should the operation of induction-coil 17 be suspended by the. presence of a car or train in block No. 2 and no waves be sentalong wire 20, the coherer 40 would ceasetto operate, but would assume the position indicated in Fig. 3, and air-pressure from tank would be shut off from bellows 75. The air in the latter would v escape through valve and the bellows the restored oscillation, 6o

would deflate, causing thered glasses 86 and 87 to cover lenses 86 and 87, showing a red or danger signal. When the bellows are nearly deflated, valve 88 will be opened by detent 90, admitting air to whistle 89, causing the latter to sound a danger-signal, and contact 91, engaging contact 92, will close the circuit of bell 93, giving an additional audible danger-signal to warn the operator to stop his car or train until the succeedingblock is cleared, to be evidenced by the coherer again taking up its operation, due to and setting the visual signal at safety and discontinuing the operation of the whistle and bell.

- Having thus described myinvention, what I claim as new, and desire to secure by Letters Patent, is-

1. Ina railway block-signaling system, a

generator of electrical oscillations foreach.

block normally operating to indicate a condition of safety and means operating under conditions of danger in any b ock to suspend the operation of the generator transmitting oscillations to the next adjacent block.

2. In a railway block-signaling system, a V

of the generator, thereby indicating danger in next adjacent block.

3. In a railway signaling system, a generator of Hertzian waves controlled by conditions of safety to propagate such oscillations and by conditions of danger to suspend the propagation thereof, and means at the place of warning to indicate the presence or absence of such oscillations.

4. In a railway signaling system, a generator of electrical oscillations, a track-circuit controlling said generator to propagate such oscillations during the continuance of safety conditions Within the area guarded by said track-circuit and to suspend said oscillations during the presence of conditions of danger Within said area,.and means at the place of warning to indicate the presence or absence of'such oscillations.

5. In a railway signaling system, a generator of electricaloscillations, a track-cu cuit controlling said generator to propagate such oscillations during the continuance of safety conditions within the area guarded by said track-circuit and to suspend said oscillations during the presence of conditions of danger within said area and means on a car or train approaching the track-circuit to indicate the presence or absence of such oscillations. i v

6. In a railway cab and block signaling system, a series of blocks, generators of Hertzian waves for the respective blocks normally operative to propagate oscillations along an adjacent block when the respective blocks are safetrack-circuits controlling the respective generators and operative to stop said generators when the corresponding blocks are at danger and means on a car or train to indicate the presence or absence of oseilla tions from the generator of the block being approached.

7. In a railway cab and block signaling system, a series of blocks generators of Hertzian waves for the respective blocks normally operative to propagate oscillations along an adjacent block when the respective blocks are safe, track-circuits controlling the respective generators and operative to stop I sald generators when the corresponding blocks are at danger, a rotary coherer on a car or train capable of responding to the oscillations, an electromagnet controlled by said coherer for rotating and denergizing the latter, a pneumatic system controlled by the movement of the coherer, and signals controlled by said pneumatic system.

8. In a railway cab and block-signaling system, a generator of Hertzian waves for each block, a wire for conducting the same, parallel with the block adjacent thereto, a track-circuit for each block operative to stop the generator when a car is in the corresponding block and a cpherer-controlled signal on each car for indicating the condition of th generator in the adjacent block.

9. In a railway cab and block signaling system, a generator of Hertzian waves for i each block, a wire for conducting the same parallel with the block adjacent thereto, a

track-circuit for each block operative to stop each car for indicating the condition of the generator in the adjacent block.

Signed by me at Chicago, county of Cook, State of Illinois, this 14th day of December,

FRANK W.'PRENTICE.

Witnesses:

ROBERT L. O'rwELL,

WILLIAM Y. PERRY. 

